An update - just got mine! So far I've mostly just been confused about how to add apps, and about why none of them seem to have any data in 'em (Trello is just blank).
I find chat/messaging pretty tough, which I get, but the Slack app seems to find a good usecase: showing when you're mentioned. It's basically the Slack notifications layer given app form.
Still super confused about how to get to glances easily.
Here are some ideas I've come up with, feel free to roll 'em:
-pong with the dial.
-skateboarding game which uses your wrist movements to do tricks
-ALERTS - the shit you really need to see before anyone else does
-Your Mood - could use the heartrate sensor + activity data to make something like a moodring.